Keyboard apparatus



(No Model.)

P. R. MGBERTY.4 KEYBOARD APPARATUS.

Patented Deo. 29, 1896.

Qi 1 g N Zmes'sefs.'

UNITED STATES PATENT OFFICE.,

FRANK R. MCBERTY, OF DOWNERS GROVE, ILLINOIS, ASSIGNOR TO THE VESTERN ELECTRIC COMPANY, OF CHICAGO, ILLINOIS.

KEYBOARD APPARATUS.

SPECIFICATION forming part of Letters Patent No. 573,992,` dated December 29, 1896. Application filed October 29,1895. Serial No. 567,239. (No modeLl To @Z whom, t may concern:

Be it known that I, FRANK R. MCBERTY, a citizen of the United States, residing at Downers Grove,in the county of D u Page and State of Illinois, have invented a certain new and useful Improvement in Keyboard Apparatus, (Case No. 30,) of which the following is a full, clear,concise,and exact description, reference being had to the accompanying drawing, forming a part of this specification.

My invention concerns the operators7 appliances of telephone-switchboards, being a new form of key and arrangement of circuits fortransmitting signaling-currents to substations.'

The obj ect of the invention is to permit the sending of such currents automatically, the operations ot connecting the source of signaling-current with the telephone-line and disconnecting it therefrom being performed incidentally to other necessary acts in the process of Limiting lines in the switchboard.

The invention consists in the combination, with the plug-circuit uniting the members of a pair of connecting-plugs and the key for connecting a telephone with the plug-circuit, of a pair of switch-springs controlled incidentally in the operation of the key adapted to disconnect one ol` the plu'gs from the other and to connect it with a source of signalingcurrent during the use of the telephone, the latter instrument being connected With the other plug. The plug with which the telephone is connected may be employed to make connection with a calling-line. Then the insertion of the other plug into a spring-jack of the required line at once connects the source of signaling-current with that line, the signaling-current being interrupted by the manipulation of the key to disconnect the telephone.

A form of the invention is shown in the drawing herewith, in which a plug-circuit equipped with the invention is represented at a switchboard wherein two telephone-lines terminate. The appliances at the substations may be of the usual type-telephones a and CU, a signal-bell CL2, a generator a3 of signaling-current, and a switch a4 for connecting the signaling apparatus and the telephones alternately with the line-circuit. The metalliccircuit line comprises two line-wires l and 2, which extend to the contact-pieces ofa springjack b in a switch board, and thence to an annunciator c near the spring-jack.

The usual plugs d and d are furnished for uniting lines by means of their spring-jacks, and a listening-keytc is provided controlling the connection of the operators telephones fj" with the conductors uniting the plugs. This key has two pairs of switchsprings c' e2 and e3 c4, all of which are thrust outward when the button of the key is depressed. Springs e and c2 have normal resting-anvils e5 and e, respectively, and alternate anvils c7 and es. Springs ed and c4 have only the anvils e9 elo, upon which they impinge when separated.

The tip g and sleeve g of plug d are connected, by conductors 3 and 4, respectively,

with the springs e and e2. The tip of plug CZ' is united by wire 5 with the spring e3 and anvil c5 of the key, and the sleeve of the plug with the spring c4 and contact e6. The anvils c7 and es constitute the terminals of a conductor 7, including the operators telephone. The anviis ci and elo form the terminals of a generator h of current suitable for operating the signal-bells a2 at the substations.

The usual clearing-out annunciator i is connected in a bridge 8 of the plug-circuit.

The key c may be left normally in position t0 sever the connection between the twoplugs, leaving the plug d connected with thetelephones f f and the plug cl connected with the generator h.

The subscriber may operate his line-annunciator c in the usual way-by operating his generator o3. The operator, responding to the call, inserts plug d (which may be denomi` nated the answering-plug) into springjack b, whereupon she nds her telephones connected with the line ready to receive the subscribers order. Having learned the number of the line with which connection is required,she inserts plug d' (the calling-plug into the spring-jack b of that line. The callin g-generator h is now connected with the line to the required station and rings the bell at the station. A moment later the operator may release the plunger of key c, whereby IOO the telephone-circuit 7 and the generator h will be disconnected from the plugsfand the latter will be united through conduct-ors 3 5 and L 6. The plu g-circuit joining the lines for conversation is then complete.

It will be observed that this device obviates all waste of time in transmitting callsignals after the establishment of connection with a line and all manipulation of special calling-keys.

The invention admits of various modifications. Hence I do not limit myself to the form shown; but

I claim as new and desire to secure by'Letters Patentl. The combination with a plug, of a telephone-circuit associated therewith, a generator of signaling-currents, a key constructed to interrupt said telephone-circuit and to conneet said generator with the plug, and an instrument through which the severed portion of the telephone-circuit is closed by said key; substantially as described.

2. The combination with an answeringplug, of a calling-plug, a plug-circuit for the plugs, a generator of signaling-currents, a telephone, and a combined listening and calling key constructed to connect the generator with the calling-plug and the telephone with the answering-plug; substantially as described. A

3. The combination with the answeringplug having a telephone associatedtherewith, of a calling-plug having a generator of calling-currents associated therewith, a plug-circuit forthe plugs, and a key constructed to sever the connection between the plugs and t0 connect the generator with the calling-plu g and the telephone with the answering-plug; substantially as described.

4. In combination two telephone-lines, one provided with a telephone and the other With a signal-bell, a conductor uniting the lines, an operators telephone and a generator of signaling-current, a key connecting said telephone with said first-mentioned line and said generator of signaling-current with said second-mentioned line, and switch-contacts in the key operated in disconnecting the generator inthe telephone adapted to complete the conductor uniting the lines, substantially as described.

In witn ess whereof I hereunto subscribe my name this 14th day of September, A. D. 1895.

FRANK R. MCBERTY.

Witnesses:

ELLA EDLER, LUCILE RUSSELL. 

